This invention pertains to article dispensing and, more particularly, concerns the dispensing of split retaining rings.
Split retaining rings have been widely employed to provide an artificial shoulder on shafts or within housing bores capable of securing machine parts against axial displacement. Installation of such retaining rings is often performed during assembly-line operations, thereby requiring smooth and rapid handling of the rings. Accordingly, numerous proposals have heretofore been made to facilitate such handling, especially in the field of dispensers which retain a stack of the rings for convenient one-at-a-time removal. In general, a split ring dispenser includes an upright support rail upon which may be installed a stack of rings, and a guide slot which guides an applicator tool for engagement and withdrawal of the bottommost ring in the stack.
Applicator tools can be of various design, one common form comprising a handle and an expandable, curved groove capable of gripping the bottom ring in a stack of rings, while displacing the remaining rings out of contact with the bottom ring. The bottom ring can thereby be extracted from the dispenser and inserted into an assembly of parts, all by manipulation of the applicator.
Although split ring dispensers have, in the past, provided effective and valuable service, room for improvement remains. For example, some dispensers employ ring retaining rails in the form of leaf springs which are mounted by rivets so as to be yieldably displaceable when engaged by an applicator. These rivets are small to conform to the necessarily narrow configuration of the rails, and are subject to failure, especially when adhesive tape is pulled from a stack of rings following installation of the stack on the rail.
Other problems can result from the intensive usage to which the dispensers are subjected, mainly during assembly-line operations. For instance, rails which are not formed of hardened material wear too rapidly. On the other hand, rails with a narrow configuration have a tendency to warp and twist when hardened, thereby creating misalignment between the rail and the guide slot. Misalignment can also result from excessive play in the pivot connection of rotatably mounted rails, as the result of repeated usage.
Another area of concern involves the need for a relatively precise spacing of the lower end of the rail from the guide slot to assure that the applicator tool is able to grip the bottom-most ring as well as displace the remaining rings therefrom. In dispensers having adjustably mounted rails, it is not uncommon for the rail to slip, thereby requiring readjustment. If this should occur during assembly line operations, valuable time may be wasted. Of course, the rail can be permanently fixed in proper location at the time of manufacture, but there is little room for error in such an operation and elaborate procedures for minimizing error can be unduly expensive.
It would be desirable then, to effectively alleviate these and other problems with a view toward improving durability, performance and cost aspects of split ring dispensers.
As regards costs, an area of particular concern arises from the need to manufacture dispenser rails of different configurations to handle retaining rings of various shapes and sizes. By reducing the number of dispenser rail designs which are needed, manufacturing expenses can be kept down.